EP0212121A2 - Process for the continuous separation of maleic anhydride from gaseous reaction mixtures - Google Patents
Process for the continuous separation of maleic anhydride from gaseous reaction mixtures Download PDFInfo
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- EP0212121A2 EP0212121A2 EP86108179A EP86108179A EP0212121A2 EP 0212121 A2 EP0212121 A2 EP 0212121A2 EP 86108179 A EP86108179 A EP 86108179A EP 86108179 A EP86108179 A EP 86108179A EP 0212121 A2 EP0212121 A2 EP 0212121A2
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- maleic anhydride
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
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- C07C51/54—Preparation of carboxylic acid anhydrides
- C07C51/573—Separation; Purification; Stabilisation; Use of additives
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- This invention relates to a process for the continuous separation of maleic anhydride (MSA) from gaseous reaction mixtures by alcohols and dicarboxylic acid diesters.
- MSA maleic anhydride
- 1,4-butanediol can be prepared from MSA by esterifying MSA with a monohydric aliphatic alcohol having 1 to 6 carbon atoms in a first stage and catalyzing the maleic acid dialkyl ester in a second stage hydrated. According to a process described in DE-PS 28 45 905, the 1,4-butanediol formation is carried out in one step, a mixture of MA and the alcohol being directly catalytically hydrogenated, without complete esterification of the MA.
- the continuous separation of MA from gaseous reaction mixtures obtained in the catalytic oxidation of hydrocarbons is carried out by treating the gaseous reaction mixture with solvents in such a way that the gaseous mixture containing MA is obtained Reaction mix with a monohydric aliphatic alcohol with 1 to 3 or 5 to 8 carbon atoms in contact, the resulting gaseous substances in countercurrent contact with a dicarboxylic acid diester and the liquid process product from the bottom.
- a gaseous reaction mixture containing MSA is brought into contact with the alcohol for the purpose of MSA absorption.
- the reaction gas is supplied below the surface of the liquid alcohol, e.g. through a dip tube.
- the reaction mixture can also be introduced directly from below into an absorption column, where liquid alcohol flows against it. The procedure in which the MSA absorption is carried out in one column or in a plurality of columns connected in series is preferred.
- the reaction mixture can also be brought into contact with gaseous alcohol.
- Reaction mixtures containing MSA are e.g. after the known catalytic oxidation of hydrocarbons such as butenes, butane or benzene.
- hydrocarbons such as butenes, butane or benzene.
- a gaseous reaction mixture with a temperature of 250 to 600 ° C flows out of the reactor, each containing Nm3 to 40 g of maleic anhydride.
- the gaseous reaction mixtures also contain water, carbon monoxide and carbon dioxide.
- columns are e.g. Absorption columns, such as bubble-cap trays, packed columns and sieve tray columns with plate numbers from 1 to 50, preferably 5 to 20, are suitable. It is expedient to work in such a way that the gaseous reaction mixture containing the MSA is introduced into the column bottom, the alcohol into the lower part of the column, advantageously above the column bottom, and the dicarboxylic acid diester is passed over the top into the column.
- the temperatures are in the bottom at 0 to 280 ° C, in the column at -20 to 150 ° C and at the top of the column at -20 to 130 ° C.
- Suitable monohydric aliphatic alcohols with 1 to 3 or 5 to 8 carbon atoms are the corresponding alkanols, such as methanol, ethanol, propanol, isopropanol, n-amyl alcohol, iso-amyl alcohol, n-hexanol, 2-ethylhexanol.
- dicarboxylic acid diesters preference is given to using diesters of C4-dicarboxylic acids, such as diesters, which on the one hand consist of succinic, fumaric or maleic acid and on the other hand from the alcohol used.
- diesters of C4-dicarboxylic acids such as diesters, which on the one hand consist of succinic, fumaric or maleic acid and on the other hand from the alcohol used.
- Based on 1 mol of MA in the gaseous starting mixture 0.2 to 10 mol of butanol and 0.2 to 20 mol of maleic acid dibutyl ester are used.
- the gas mixture and the alcohol are introduced as described into the bottom or the lower part of the column.
- the lower part of the column is understood to mean the part above the bottom to the second to fifth plate.
- a possibly occurring second liquid phase which mainly consists of water, is discharged from the column.
- a liquid mixture is discharged, from which one boils more easily than the dicarboxylic acid diester in a separate distillation device, such as a distillation column Parts distilled off, which are returned to the lower part of the column.
- the dicarboxylic acid diester obtained in this separate distillation as the bottom product is fed to the absorption column overhead.
- the column is operated so that the temperature in the bottom tray is between 0 and 150 ° C, preferably between 25 and 100 ° C, in the central part of the column a temperature of -20 to 150 ° C, preferably from 0 to 65 ° C and at the top of the column a temperature of -20 to 130 ° C, preferably 0 to 40 ° C.
- the MA in the column is predominantly converted into the mono- and dialkyl maleate.
- the gaseous accompanying substances of the MSA are discharged via the top of the column, while some of the water may leave the column through the side draw.
- the liquid process product which is taken from the bottom of the column has, for example, the following composition: 0.01 to 93% by weight of alcohol, 0.7 to 79% by weight of maleic acid monoalkyl ester, 0.5 to 95% by weight of maleic acid dialkyl ester, up to 50 % By weight MSA, maleic acid and fumaric acid.
- the maleic acid dialkyl ester usually contains considerable amounts of the isomeric fumaric acid dialkyl ester.
- the liquid mixture is ideal for hydrogenation to obtain 1,4-butanediol.
- the maleic acid dialkyl ester can then be hydrogenated to 1,4-butanediol in a manner known per se.
- the new process makes it possible to convert the MSA from the reaction gases quantitatively and largely avoiding absorbent losses into a liquid mixture which has a high concentration of the half and diester of maleic acid and which is excellent for the hydrogenation to obtain 1,4-butanediol is suitable. Surprisingly, disruptive deposits of crystals of maleic acid and / or fumaric acid do not occur in the procedure according to the invention.
- a nitrogen stream of 200 Nl / h (normal liters per hour) is loaded in a saturation vessel with MSA and with water vapor so that it contains 0.5 vol.% (4.5 g / h) MSA and 5 vol.% Water.
- the gas stream thus produced largely corresponds to a gaseous reaction mixture which is obtained in the known air oxidation of butane, butenes or also benzene for the purpose of producing MA.
- the gas mixture (1) is introduced into a flask (2) charged with 1/2 liter of n-amyl alcohol at the start of the experiment at a temperature of 60 ° C.
- the piston is equipped with a feed line (3).
- a liquid reaction mixture is withdrawn at regular intervals through a discharge line (4) so that the liquid level in the flask remains constant.
- a shot of a bubble tray column (5) with three bubble trays is attached to the piston and is equipped with a sampling port (6).
- the temperature in this part of the column is kept at 50.degree. 10 ml / h of amyl alcohol are introduced into the flask (2) via the feed line (3).
- phase separator (7) On the column part (5) there is a phase separator (7) provided with an outlet connection (8) and kept at 25 ° C., through which a possibly occurring second liquid phase with a higher density (aqueous phase) can be discharged from the column. On the phase separator (7) there are additional shots with a total of 18 bell bottoms (9), which are kept at 25 ° C.
- a drain connection (10) is installed three trays above the phase separator (7), with which the liquid absorbate is discharged from the column part above and fed to a distillation device. 20 ml / h of di-succinate are fed in via the top of the column (11). At the same time, a gas stream leaves the column top (12).
- the gaseous MSA (4.5 g / h) is again found in the liquid mixture that accumulates in the lower part of the apparatus, mainly in the form of the esters.
- the following composition is determined by GC and HPLC analysis of the flask discharge (4): 13.5% by weight of n-amyl alcohol, 61% by weight of maleic acid monoamyl ester, 18% by weight of maleic acid diamine ester and 7% by weight of MSA, maleic acid and fumaric acid.
- MSA, maleic acid, fumaric acid nor half-esters can already be detected at the outlet connection (6).
- Example 1 The procedure is as described in Example 1, but instead of n-amyl alcohol, methanol is used as the absorbent for MA and the dimethyl ester of dimethyl ester is used for the exhaust gas scrubbing.
- the flask (2) is charged with 500 ml of the alcohol at the start of the experiment; 10 ml / h of methanol are fed in via feed line (3), and 20 ml / h of dimethyl maleate are added to the top of the column (11).
- the part of the column above the phase separator (7) is kept at 20 ° C. After five days of experimentation, a steady state occurs and the following results are obtained:
- the gaseous MSA (4.5 g / h) is found again in the liquid mixture that accumulates in the lower part of the apparatus, mainly in the form of the esters.
- the following composition is determined by GC and HPLC analysis of the flask discharge (4): 5.9% by weight of methanol, 69% by weight of monomethyl maleate; 1.1% by weight of dimethyl maleate and 22% by weight of MSA.
- Example 1 The procedure is as described in Example 1, but instead of n-amyl alcohol, ethanol is used as the absorbent for MA and instead of diethyl succinate, diethyl fumarate is used for exhaust gas scrubbing.
- the flask (2) is charged with 500 ml of the alcohol at the start of the experiment; 10 ml / h of ethanol are fed in via feed line (3), and 20 ml / h of diethyl fumarate are added to the top of the column (11).
- the part of the column above the phase separator (7) is kept at 20 ° C. After five days of experimentation, a steady state occurs and the following results are obtained:
- the gaseous MSA (4.5 g / h) is found again in the liquid mixture that accumulates in the lower part of the apparatus, mainly in the form of the esters.
- the following composition is determined by GC and HPLC analysis of the flask discharge (4): 2.5% by weight of ethanol, 79% by weight of maleic acid monoethyl ester; 17.1% by weight of diethyl maleate and ⁇ 0.1% by weight of MA.
Abstract
Description
Diese Erfindung betrifft ein Verfahren zur kontinuierlichen Abscheidung von Maleinsäureanhydrid (MSA) aus gasförmigen Reaktionsgemischen durch Alkohole und Dicarbonsäurediester.This invention relates to a process for the continuous separation of maleic anhydride (MSA) from gaseous reaction mixtures by alcohols and dicarboxylic acid diesters.
Aus der DE-OS 25 43 673 ist bekannt, daß man 1,4-Butandiol aus MSA dadurch herstellen kann, daß man in einer ersten Stufe MSA mit einem einwertigen aliphatischen Alkohol mit 1 bis 6 Kohlenstoffatomen verestert und den Maleinsäuredialkylester in einer zweiten Stufe katalytisch hydriert. Nach einem in der DE-PS 28 45 905 beschriebenen Verfahren führt man die 1,4-Butandiol-Bildung in einer Stufe durch, wobei man ein Gemisch aus MSA und dem Alkohol unter Verzicht auf eine vollständige Veresterung des MSA unmittelbar katalytisch hydriert.From DE-OS 25 43 673 it is known that 1,4-butanediol can be prepared from MSA by esterifying MSA with a monohydric aliphatic alcohol having 1 to 6 carbon atoms in a first stage and catalyzing the maleic acid dialkyl ester in a second stage hydrated. According to a process described in DE-PS 28 45 905, the 1,4-butanediol formation is carried out in one step, a mixture of MA and the alcohol being directly catalytically hydrogenated, without complete esterification of the MA.
In der DE-OS 31 06 819 wird der Vorschlag gemacht, das MSA aus einem gasförmigen Reaktionsgemisch durch eine Wäsche mit 1,4-Butandiol abzuscheiden. Das dabei erhältliche Gemisch wird zum 1,4-Butandiol hydriert. Man muß hierbei zwar kein Lösungsmittel abtrennen, doch gelingt es nicht, sowohl hohe Konzentrationen an MSA bzw. an monomeren MSA-Folgeprodukten im Absorbat zu erhalten als auch die unerwünschte Bildung von Oligomeren und Polymeren aus Butandiol und MSA zu verhindern. Beides ist aber wünschenswert, denn hohe Raum-Zeit-Ausbeuten kann man nur mit hohen Absorbat-Konzentrationen erzielen, und Oligomere und Polymere beeinträchtigen die Katalysatoren bei der nachfolgenden Hydrierung.In DE-OS 31 06 819, the proposal is made to separate the MA from a gaseous reaction mixture by washing with 1,4-butanediol. The resulting mixture is hydrogenated to 1,4-butanediol. It is not necessary to separate off a solvent here, but it is not possible to obtain both high concentrations of MSA or monomeric MSA secondary products in the absorbate and to prevent the undesired formation of oligomers and polymers from butanediol and MSA. Both are desirable, however, because high space-time yields can only be achieved with high absorbate concentrations, and oligomers and polymers impair the catalysts in the subsequent hydrogenation.
Versucht man, für eine Butandiol-Herstellung geeignete Gemische aus Alkanol und MSA herzustellen, so ergeben sich durch den hohen Gehalt des Abgases an Alkanol so erhebliche technische Schwierigkeiten, daß eine Alkoholwäsche mit wirtschaftlich vertretbarem Aufwand nicht betrieben werden kann. Es bestand deshalb die Aufgabe, ein Verfahren zum Auswaschen von MSA aus Reaktionsgasen mit Lösungsmitteln zu finden, mit dem man auf möglichst wirtschaftliche Weise ein flüssiges Gemisch erhält, das sich vorteilhaft zur Gewinnung von 1,4-Butandiol hydrieren läßt.If one tries to produce mixtures of alkanol and MA which are suitable for the production of butanediol, the high content of alkanol in the exhaust gas results in such considerable technical difficulties that alcohol washing cannot be carried out with economically justifiable effort. The object was therefore to find a process for washing out MA from reaction gases with solvents, with which a liquid mixture can be obtained which is as economical as possible and which can advantageously be hydrogenated to obtain 1,4-butanediol.
Bei dem Verfahren der Erfindung, durch das diese Aufgabe gelöst wird, nimmt man die kontinuierliche Abscheidung von MSA aus gasförmigen Reaktionsgemischen, die man bei der katalytischen Oxidation von Kohlenwasserstoffen erhält, durch Behandlung des gasförmigen Reaktionsgemischs mit Lösungsmitteln so vor, daß man das MSA enthaltende gasförmige Reaktions gemisch mit einem einwertigen aliphatischen Alkohol mit 1 bis 3 oder 5 bis 8 Kohlenstoffatomen in Kontakt bringt, die dabei anfallenden gasförmigen Stoffe im Gegenstrom mit einem Dicarbonsäurediester in Berührung bringt und das flüssige Verfahrensprodukt dem Sumpf entnimmt.In the process of the invention by which this object is achieved, the continuous separation of MA from gaseous reaction mixtures obtained in the catalytic oxidation of hydrocarbons is carried out by treating the gaseous reaction mixture with solvents in such a way that the gaseous mixture containing MA is obtained Reaction mix with a monohydric aliphatic alcohol with 1 to 3 or 5 to 8 carbon atoms in contact, the resulting gaseous substances in countercurrent contact with a dicarboxylic acid diester and the liquid process product from the bottom.
Nach dem erfindungsgemäßen Verfahren bringt man ein MSA enthaltendes gasförmiges Reaktionsgemisch zum Zwecke der MSA-Absorption mit dem Alkohol in Kontakt. Die Reaktionsgaszufuhr erfolgt bei einer zweckmäßigen Ausführungsform des Verfahrens unterhalb der Oberfläche des flüssigen Alkohols, z.B. durch ein Tauchrohr. Das Reaktionsgemisch kann aber auch direkt von unten in eine Absorptionskolonne eingeleitet werden, wo ihm flüssiger Alkohol entgegenströmt. Die Arbeitsweise, bei der man die MSA-Absorption in einer Kolonne oder in mehreren hintereinandergeschalteten Kolonnen durchführt, ist bevorzugt. Man kann das Reaktionsgemisch auch mit gasförmigem Alkohol in Kontakt bringen.In the process according to the invention, a gaseous reaction mixture containing MSA is brought into contact with the alcohol for the purpose of MSA absorption. In a convenient embodiment of the process, the reaction gas is supplied below the surface of the liquid alcohol, e.g. through a dip tube. However, the reaction mixture can also be introduced directly from below into an absorption column, where liquid alcohol flows against it. The procedure in which the MSA absorption is carried out in one column or in a plurality of columns connected in series is preferred. The reaction mixture can also be brought into contact with gaseous alcohol.
MSA enthaltende Reaktionsgemische werden z.B. nach der an sich bekannten katalytischen Oxidation von Kohlenwasserstoffen wie Butene, Butan oder auch Benzol, erhalten. Bei diesem bekannten Oxidationsverfahren strömt aus dem Reaktor ein gasförmiges Reaktionsgemisch mit einer Temperatur von 250 bis 600°C, das je Nm³ bis 40 g Maleinsäureanhydrid enthält. Außerdem enthalten die gasförmigen Reaktionsgemische neben nicht umgesetztem Kohlenwasserstoff Wasser, Kohlenmonoxid und Kohlendioxid.Reaction mixtures containing MSA are e.g. after the known catalytic oxidation of hydrocarbons such as butenes, butane or benzene. In this known oxidation process, a gaseous reaction mixture with a temperature of 250 to 600 ° C flows out of the reactor, each containing Nm³ to 40 g of maleic anhydride. In addition to the unreacted hydrocarbon, the gaseous reaction mixtures also contain water, carbon monoxide and carbon dioxide.
Als Kolonnen sind z.B. Absorptionskolonnen, wie Glockenboden-, Füllkörper- und Siebbodenkolonnen mit Bodenzahlen von 1 bis 50, vorzugsweise 5 bis 20 geeignet. Man arbeitet zweckmäßigerweise so, daß man das das MSA enthaltende gasförmige Reaktionsgemisch in den Kolonnensumpf, den Alkohol in den unteren Teil der Kolonne, vorteilhaft oberhalb des Kolonnensumpfes und den Dicarbonsäurediester über den Kopf in die Kolonne einleitet. Die Temperaturen liegen im Sumpf bei 0 bis 280°C, in der Kolonne bei -20 bis 150°C und am Kopf der Kolonne bei -20 bis 130°C.As columns are e.g. Absorption columns, such as bubble-cap trays, packed columns and sieve tray columns with plate numbers from 1 to 50, preferably 5 to 20, are suitable. It is expedient to work in such a way that the gaseous reaction mixture containing the MSA is introduced into the column bottom, the alcohol into the lower part of the column, advantageously above the column bottom, and the dicarboxylic acid diester is passed over the top into the column. The temperatures are in the bottom at 0 to 280 ° C, in the column at -20 to 150 ° C and at the top of the column at -20 to 130 ° C.
Als einwertige aliphatische Alkohole mit 1 bis 3 oder 5 bis 8 C-Atomen kommen die entsprechenden Alkanole, wie Methanol, Ethanol, Propanol, Isopropanol, n-Amylalkohol, iso-Amylalkohol, n-Hexanol, 2-Ethylhexanol in Frage. Als Dicarbonsäurediester verwendet man bevorzugt Diester von C₄-Dicarbonsäuren, wie die Diester, die einerseits aus der Bernstein-, Fumar- oder Maleinsäure und andererseits aus dem eingesetzten Alkohol bestehen. Bezogen auf 1 Mol MSA im gasförmigen Ausgangsgemisch wendet man 0,2 bis 10 Mol Butanol und 0,2 bis 20 Mol Maleinsäuredibutylester an.Suitable monohydric aliphatic alcohols with 1 to 3 or 5 to 8 carbon atoms are the corresponding alkanols, such as methanol, ethanol, propanol, isopropanol, n-amyl alcohol, iso-amyl alcohol, n-hexanol, 2-ethylhexanol. As dicarboxylic acid diesters, preference is given to using diesters of C₄-dicarboxylic acids, such as diesters, which on the one hand consist of succinic, fumaric or maleic acid and on the other hand from the alcohol used. Based on 1 mol of MA in the gaseous starting mixture, 0.2 to 10 mol of butanol and 0.2 to 20 mol of maleic acid dibutyl ester are used.
Nach einer bevorzugten Arbeitsweise, bei der man die kontinuierliche Abscheidung des MSA in einer Kolonne vornimmt, werden das Gasgemisch und der Alkohol wie geschildert in den Sumpf bzw. den unteren Teil der Kolonne eingeleitet. Als unterer Teil der Kolonne wird der Teil oberhalb des Sumpfes bis zum zweiten bis fünften Boden verstanden.According to a preferred procedure, in which the MSA is continuously separated off in a column, the gas mixture and the alcohol are introduced as described into the bottom or the lower part of the column. The lower part of the column is understood to mean the part above the bottom to the second to fifth plate.
Oberhalb der Einleitung des Alkohols, also oberhalb des zweiten bis fünften Bodens, wird eine eventuell auftretende zweite flüssige Phase, die hauptsächlich aus Wasser besteht, aus der Kolonne ausgeschleust. Aus dem mittleren Teil der Kolonne, unter dem der Bereich bis zu fünf Böden oberhalb der Entnahmestellen für die wäßrige Phase verstanden wird, schleust man ein flüssiges Gemisch aus, aus dem man in einer separaten Destillationsvorrichtung, wie einer Destillationskolonne, die leichter als der Dicarbonsäurediester siedenden Anteile abdestilliert, die man in den unteren Teil der Kolonne zurückführt. Der bei dieser separaten Destillation als Sumpfprodukt anfallende Dicarbonsäurediester wird der Absorptionskolonne über Kopf zugeführt. Die Kolonne wird dabei so betrieben, daß die Temperatur im untersten Boden zwischen 0 und 150°C, vorzugsweise zwischen 25 und 100°C liegt, sich im mittleren Teil der Kolonne eine Temperatur von -20 bis 150°C, vorzugsweise von 0 bis 65°C und am Kolonnenkopf eine Temperatur von -20 bis 130°C, vorzugsweise 0 bis 40°C einstellt.Above the introduction of the alcohol, that is to say above the second to fifth tray, a possibly occurring second liquid phase, which mainly consists of water, is discharged from the column. From the middle part of the column, which means the area up to five trays above the tapping points for the aqueous phase, a liquid mixture is discharged, from which one boils more easily than the dicarboxylic acid diester in a separate distillation device, such as a distillation column Parts distilled off, which are returned to the lower part of the column. The dicarboxylic acid diester obtained in this separate distillation as the bottom product is fed to the absorption column overhead. The column is operated so that the temperature in the bottom tray is between 0 and 150 ° C, preferably between 25 and 100 ° C, in the central part of the column a temperature of -20 to 150 ° C, preferably from 0 to 65 ° C and at the top of the column a temperature of -20 to 130 ° C, preferably 0 to 40 ° C.
Unter den Bedingungen der erfindungsgemäßen Absorption wird das MSA in der Kolonne überwiegend in den Maleinsäuremono- und -dialkylester überführt. Die gasförmigen Begleitstoffe des MSA werden über Kopf der Kolonne abgeleitet, während eventuell ein Teil des Wassers die Kolonne durch den Seitenabzug verläßt. Das flüssige Verfahrensprodukt, das man dem Sumpf der Kolonne entnimmt, hat z.B. folgende Zusammensetzung: 0,01 bis 93 Gew.% Alkohol, 0,7 bis 79 Gew.% Maleinsäuremonoalkylester, 0,5 bis 95 Gew.% Maleinsäuredialkylester, bis zu 50 Gew.% MSA, Maleinsäure und Fumarsäure. Der Maleinsäuredialkylester enthält gewöhnlich erhebliche Anteile an dem isomeren Fumarsäuredialkylester. Das flüssige Gemisch eignet sich hervorragend für die Hydrierung zur Gewinnung von 1,4-Butandiol. Hierzu empfiehlt es sich, das flüssige Gemisch zum Zwecke der Vervollständigung der Veresterung z.B. auf 100 bis 250°C zu erhitzen, wobei man das Reaktionswasser mit dem überschüssigen Alkohol abtreibt und somit den für das erfindungsgemäße Verfahren benötigten Alkohol zurückgewinnt. Der Maleinsäuredialkylester kann dann auf an sich bekannte Weise zu 1,4-Butandiol hydriert werden.Under the conditions of the absorption according to the invention, the MA in the column is predominantly converted into the mono- and dialkyl maleate. The gaseous accompanying substances of the MSA are discharged via the top of the column, while some of the water may leave the column through the side draw. The liquid process product which is taken from the bottom of the column has, for example, the following composition: 0.01 to 93% by weight of alcohol, 0.7 to 79% by weight of maleic acid monoalkyl ester, 0.5 to 95% by weight of maleic acid dialkyl ester, up to 50 % By weight MSA, maleic acid and fumaric acid. The maleic acid dialkyl ester usually contains considerable amounts of the isomeric fumaric acid dialkyl ester. The liquid mixture is ideal for hydrogenation to obtain 1,4-butanediol. For this purpose, it is advisable to heat the liquid mixture for the purpose of completing the esterification, for example to 100 to 250 ° C., the water of reaction being driven off with the excess alcohol and thus the alcohol required for the process according to the invention being recovered. The maleic acid dialkyl ester can then be hydrogenated to 1,4-butanediol in a manner known per se.
Das neue Verfahren ermöglicht es, das MSA aus den Reaktionsgasen quantitativ und unter weitgehender Vermeidung von Absorptionsmittel-Verlusten in ein flüssiges Gemisch zu überführen, das eine hohe Konzentration an dem Halb- und Diester der Maleinsäure aufweist und das sich hervorragend für die Hydrierung zur Gewinnung von 1,4-Butandiol eignet. Überraschenderweise treten bei der erfindungsgemäßen Arbeitsweise störende Abscheidungen von Kristallen aus Maleinsäure und/oder Fumarsäure nicht auf.The new process makes it possible to convert the MSA from the reaction gases quantitatively and largely avoiding absorbent losses into a liquid mixture which has a high concentration of the half and diester of maleic acid and which is excellent for the hydrogenation to obtain 1,4-butanediol is suitable. Surprisingly, disruptive deposits of crystals of maleic acid and / or fumaric acid do not occur in the procedure according to the invention.
Ein Stickstoffstrom von 200 Nl/h (Normalliter pro Stunde) wird in einem Sättigungsgefäß mit MSA und mit Waserdampf so beladen, daß er 0,5 Vol.% (4,5 g/h) MSA und 5 Vol.% Waser enthält. Der so hergestellte Gasstrom entspricht bezüglich dieser Komponenten weitgehend einem gasförmigen Reaktionsgemisch, das man bei der bekannten Luftoxidation von Butan, Butenen oder auch Benzol zum Zwecke der Herstellung von MSA erhält.A nitrogen stream of 200 Nl / h (normal liters per hour) is loaded in a saturation vessel with MSA and with water vapor so that it contains 0.5 vol.% (4.5 g / h) MSA and 5 vol.% Water. With regard to these components, the gas stream thus produced largely corresponds to a gaseous reaction mixture which is obtained in the known air oxidation of butane, butenes or also benzene for the purpose of producing MA.
Das Gasgemisch (1) wird in einem zu Versuchsbeginn mit 1/2 Liter n-Amylalkohol beschickten Kolben (2) bei einer Temperatur von 60°C getaucht eingeleitet. Der Kolben ist mit einer Zuleitung (3) ausgerüstet. Durch eine Ableitung (4) wird in regelmäßigen Zeitabständen flüssiges Reaktionsgemisch entnommen, so daß der Flüssigkeitsstand im Kolben konstant bleibt. Auf dem Kolben ist ein Schuß einer Glockenbodenkolonne (5) mit drei Glockenböden angebracht, der mit einem Probeentnahmestutzen (6) ausgerüstet ist. Die Temperatur hält man in diesem Teil der Kolonne auf 50°C. Über die Zuleitung (3) werden 10 ml/h Amylalkohol in den Kolben (2) eingeleitet. Auf dem Kolonnenteil (5) befindet sich ein mit einem Ablaßstutzen (8) versehener auf 25°C gehaltener Phasenabscheider (7), durch den man eine möglicherweise auftretende zweite flüssige Phase mit höherer Dichte (wäßrige Phase) aus der Kolonne ausschleusen kann. Auf dem Phasenabscheider (7) sind weitere Schüsse mit insgesamt 18 Glockenböden (9) angebracht, die auf 25°C gehalten werden.The gas mixture (1) is introduced into a flask (2) charged with 1/2 liter of n-amyl alcohol at the start of the experiment at a temperature of 60 ° C. The piston is equipped with a feed line (3). A liquid reaction mixture is withdrawn at regular intervals through a discharge line (4) so that the liquid level in the flask remains constant. A shot of a bubble tray column (5) with three bubble trays is attached to the piston and is equipped with a sampling port (6). The temperature in this part of the column is kept at 50.degree. 10 ml / h of amyl alcohol are introduced into the flask (2) via the feed line (3). On the column part (5) there is a phase separator (7) provided with an outlet connection (8) and kept at 25 ° C., through which a possibly occurring second liquid phase with a higher density (aqueous phase) can be discharged from the column. On the phase separator (7) there are additional shots with a total of 18 bell bottoms (9), which are kept at 25 ° C.
Drei Böden über dem Phasenabscheider (7) ist ein Ablaßstutzen (10) installiert, mit dem man das flüssige Absorbat aus dem darüberliegenden Kolonnenteil ausschleust und einer Destillationsvorrichtung zuführt. Über den Kopf der Kolonne werden 20 ml/h Bernsteinsäurediamylester zugeführt (11). Gleichzeitig verläßt ein Gasstrom den Kolonnenkopf (12).A drain connection (10) is installed three trays above the phase separator (7), with which the liquid absorbate is discharged from the column part above and fed to a distillation device. 20 ml / h of di-succinate are fed in via the top of the column (11). At the same time, a gas stream leaves the column top (12).
Nach fünftägiger Versuchsdauer stellt sich ein stationärer Zustand ein, und man erhält die folgenden Ergebnisse:After five days of experimentation, a steady state occurs and the following results are obtained:
Das gasförmig zugeführte MSA (4,5 g/h) findet sich wieder im flüssigen Gemisch, das sich im unteren Teil der Apparatur ansammelt, und zwar überwiegend in Form der Ester. Durch GC- und HPLC-Analyse des Kolbenaustrags (4) wird folgende Zusammensetzung ermittelt: 13,5 Gew.% n-Amylalkohol, 61 Gew.% Maleinsäuremonoamylester, 18 Gew.% Maleinsäurediamylester und 7 Gew.% MSA, Maleinsäure und Fumarsäure. Bereits am Ablaßstutzen (6) lassen sich weder MSA, Maleinsäure, Fumarsäure noch Halbester nachweisen. Am Phasenabscheider (7) werden 6 bis 9 g/h einer wäßrigen Phase ausgeschleust, die 6 bis 7 Gew.% n-Amylalkohol enthält. Das über den Ablaßstutzen (10) entnommene flüssige Absorbat enthält 6,1 Gew.% n-Amylalkohol und 94 Gew.% Bernsteinsäurediamylester. Die Amylalkohol-Konzentration geht im oberen Teil der Kolonne (9) soweit zurück, daß mit dem Abgas (12) neben 3,0 g/h Wasser und weniger als 0,01 g/h Bernsteinsäurediamylester weniger als 0,01 g/h n-Amylalkohol ausgetragen werden.The gaseous MSA (4.5 g / h) is again found in the liquid mixture that accumulates in the lower part of the apparatus, mainly in the form of the esters. The following composition is determined by GC and HPLC analysis of the flask discharge (4): 13.5% by weight of n-amyl alcohol, 61% by weight of maleic acid monoamyl ester, 18% by weight of maleic acid diamine ester and 7% by weight of MSA, maleic acid and fumaric acid. Neither MSA, maleic acid, fumaric acid nor half-esters can already be detected at the outlet connection (6). 6 to 9 g / h of an aqueous phase which contains 6 to 7% by weight of n-amyl alcohol are removed at the phase separator (7). The liquid absorbate withdrawn via the outlet connection (10) contains 6.1% by weight of n-amyl alcohol and 94% by weight of succinic acid diamine ester. The amyl alcohol concentration in the upper part of the column (9) decreases to such an extent that with the exhaust gas (12), in addition to 3.0 g / h of water and less than 0.01 g / h of succinic acid, less than 0.01 g / h of n -Amyl alcohol to be discharged.
Man verfährt wie in Beispiel 1 beschrieben, wobei man jedoch anstelle von n-Amylalkohol Methanol als Absorptionsmittel für MSA und anstelle von Bernsteinsäurediamylester Maleinsäuredimethylester für die Abgaswäsche verwendet. Wie in Beispiel 1 wird der Kolben (2) bei Versuchsbeginn mit 500 ml des Alkohols beschickt; über die Zuleitung (3) werden 10 ml/h Methanol zugeführt, und auf den Kopf der Kolonne werden 20 ml/h Maleinsäuredimethylester gegeben (11).The procedure is as described in Example 1, but instead of n-amyl alcohol, methanol is used as the absorbent for MA and the dimethyl ester of dimethyl ester is used for the exhaust gas scrubbing. As in Example 1, the flask (2) is charged with 500 ml of the alcohol at the start of the experiment; 10 ml / h of methanol are fed in via feed line (3), and 20 ml / h of dimethyl maleate are added to the top of the column (11).
Der Teil der Kolonne oberhalb des Phasenabscheiders (7) wird auf 20°C gehalten. Nach fünftägiger Versuchsdauer stellt sich ein stationärer Zustand ein, und man erhält die folgenden Ergebnisse:
Das gasförmige MSA (4,5 g/h) findet sich wieder im flüssigen Gemisch, das sich im unteren Teil der Apparatur ansammelt, und zwar überwiegend in Form der Ester. Durch GC- und HPLC-Analyse des Kolbenaustrags (4) wird folgende Zusammensetzung ermittelt: 5,9 Gew.% Methanol, 69 Gew.% Maleinsäuremonomethylester; 1,1 Gew.% Maleinsäuredimethylester und 22 Gew.% MSA.The part of the column above the phase separator (7) is kept at 20 ° C. After five days of experimentation, a steady state occurs and the following results are obtained:
The gaseous MSA (4.5 g / h) is found again in the liquid mixture that accumulates in the lower part of the apparatus, mainly in the form of the esters. The following composition is determined by GC and HPLC analysis of the flask discharge (4): 5.9% by weight of methanol, 69% by weight of monomethyl maleate; 1.1% by weight of dimethyl maleate and 22% by weight of MSA.
Bereits am Ablaßstutzen (6) lassen sich weder MSA, Maleinsäure, Fumarsäure noch Halbester nachweisen. Am Phasenabscheider (7) fällt keine wäßrige Phase an.Neither MSA, maleic acid, fumaric acid nor half-esters can be detected even at the outlet connection (6). No aqueous phase is obtained at the phase separator (7).
Man verfährt wie in Beispiel 1 beschrieben, wobei man jedoch anstelle von n-Amylalkohol Ethanol als Absorptionsmittel für MSA und anstelle von Bernsteinsäurediamylester Fumarsäurediethylester für die Abgaswäsche verwendet. Wie in Beispiel 1 wird der Kolben (2) bei Versuchsbeginn mit 500 ml des Alkohols beschickt; über die Zuleitung (3) werden 10 ml/h Ethanol zugeführt, und auf den Kopf der Kolonne werden 20 ml/h Fumarsäurediethylester gegeben (11).The procedure is as described in Example 1, but instead of n-amyl alcohol, ethanol is used as the absorbent for MA and instead of diethyl succinate, diethyl fumarate is used for exhaust gas scrubbing. As in Example 1, the flask (2) is charged with 500 ml of the alcohol at the start of the experiment; 10 ml / h of ethanol are fed in via feed line (3), and 20 ml / h of diethyl fumarate are added to the top of the column (11).
Der Teil der Kolonne oberhalb des Phasenabscheiders (7) wird auf 20°C gehalten. Nach fünftägiger Versuchsdauer stellt sich ein stationärer Zustand ein, und man erhält die folgenden Ergebnisse:
Das gasförmige MSA (4,5 g/h) findet sich wieder im flüssigen Gemisch, das sich im unteren Teil der Apparatur ansammelt, und zwar überwiegend in Form der Ester. Durch GC- und HPLC-Analyse des Kolbenaustrags (4) wird folgende Zusammensetzung ermittelt: 2,5 Gew.% Ethanol, 79 Gew.% Maleinsäuremonoethylester; 17,1 Gew.% Maleinsäurediethylester und <0,1 Gew.% MSA.The part of the column above the phase separator (7) is kept at 20 ° C. After five days of experimentation, a steady state occurs and the following results are obtained:
The gaseous MSA (4.5 g / h) is found again in the liquid mixture that accumulates in the lower part of the apparatus, mainly in the form of the esters. The following composition is determined by GC and HPLC analysis of the flask discharge (4): 2.5% by weight of ethanol, 79% by weight of maleic acid monoethyl ester; 17.1% by weight of diethyl maleate and <0.1% by weight of MA.
Bereits am Ablaßstutzen (6) lassen sich weder MSA, Maleinsäure, Fumarsäure noch Halbester nachweisen. Am Phasenabscheider (7) fällt keine wäßrige Phase an.Neither MSA, maleic acid, fumaric acid nor half-esters can already be detected at the outlet connection (6). No aqueous phase is obtained at the phase separator (7).
Man verfährt wie in Beispiel 1 bis 3 beschrieben, wobei man jedoch auf die Zufuhr des Alkohols (3) verzichtet und den am Kopf der Kolonne zugeführten Diester (11 nicht über den Ablaßstutzen (10) am oberen Teil der Kolonne, sondern über die Ableitung (4) am Kolben (2) wieder entnimmt.The procedure is as described in Examples 1 to 3, except that the alcohol (3) is dispensed with and the diester (11) fed in at the top of the column is not via the discharge port (10) at the upper part of the column but via the discharge ( 4) on the piston (2) again.
Innerhalb eines Tages kristallisiert Maleinsäure in der Kolonne aus, so daß die Absorption abgebrochen werden muß. Erhöht man in dem Versuch die Zugabe des Diesters auf 100 ml/h, so läßt sich die störende Kristallbildung zwar verhindern, aber man erhält dabei ein flüssiges Verfahrensprodukt, das vor einer Hydrierung zum Zwecke der Herstellung von 1,4-Butandiol eine zusätzliche Anreicherungsstufe erforderlich machen würde.Maleic acid crystallizes out in the column within one day, so that the absorption must be stopped. If the addition of the diester is increased to 100 ml / h in the experiment, the disruptive crystal formation can be prevented, but a liquid process product is obtained which requires an additional enrichment step before hydrogenation for the purpose of producing 1,4-butanediol would do.
Claims (8)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3521768 | 1985-06-19 | ||
DE19853521768 DE3521768A1 (en) | 1985-06-19 | 1985-06-19 | METHOD FOR CONTINUOUSLY SEPARATING MALEIC ACID ANHYDRIDE FROM GAS SHAPED REACTION MIXTURES |
Publications (3)
Publication Number | Publication Date |
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EP0212121A2 true EP0212121A2 (en) | 1987-03-04 |
EP0212121A3 EP0212121A3 (en) | 1988-09-07 |
EP0212121B1 EP0212121B1 (en) | 1991-02-06 |
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EP86108179A Expired - Lifetime EP0212121B1 (en) | 1985-06-19 | 1986-06-14 | Process for the continuous separation of maleic anhydride from gaseous reaction mixtures |
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EP (1) | EP0212121B1 (en) |
JP (1) | JPH0680051B2 (en) |
DE (2) | DE3521768A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6433192B1 (en) | 1998-04-23 | 2002-08-13 | Basf Aktiengesellschaft | Method for producing mixtures of 1,4-butanediol, tetrahydrofuran and γ-butyrolactone |
CN103476812A (en) * | 2011-05-11 | 2013-12-25 | 亨斯迈石油化学有限责任公司 | Improved solvent for recovery of maleic anhydride from a gas stream |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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DE19806038A1 (en) * | 1998-02-13 | 1999-08-19 | Basf Ag | Process for the separation of maleic anhydride from mixtures containing maleic anhydride by stripping |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0149144B1 (en) * | 1983-12-21 | 1986-11-05 | BASF Aktiengesellschaft | Process for the continuous separation of maleic anhydride from gaseous reaction mixtures |
-
1985
- 1985-06-19 DE DE19853521768 patent/DE3521768A1/en not_active Withdrawn
-
1986
- 1986-06-10 JP JP61132918A patent/JPH0680051B2/en not_active Expired - Lifetime
- 1986-06-14 EP EP86108179A patent/EP0212121B1/en not_active Expired - Lifetime
- 1986-06-14 DE DE8686108179T patent/DE3677427D1/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0149144B1 (en) * | 1983-12-21 | 1986-11-05 | BASF Aktiengesellschaft | Process for the continuous separation of maleic anhydride from gaseous reaction mixtures |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6433192B1 (en) | 1998-04-23 | 2002-08-13 | Basf Aktiengesellschaft | Method for producing mixtures of 1,4-butanediol, tetrahydrofuran and γ-butyrolactone |
CN103476812A (en) * | 2011-05-11 | 2013-12-25 | 亨斯迈石油化学有限责任公司 | Improved solvent for recovery of maleic anhydride from a gas stream |
CN103476812B (en) * | 2011-05-11 | 2016-05-04 | 亨斯迈石油化学有限责任公司 | For reclaim the improved solvent of maleic anhydride from air-flow |
Also Published As
Publication number | Publication date |
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DE3521768A1 (en) | 1987-01-02 |
EP0212121B1 (en) | 1991-02-06 |
JPH0680051B2 (en) | 1994-10-12 |
EP0212121A3 (en) | 1988-09-07 |
JPS61291580A (en) | 1986-12-22 |
DE3677427D1 (en) | 1991-03-14 |
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